Executive Summary

Westinghuuse Campany requested Lus Alamus Teehnieal Assueiates. Ina.
tn malte an independent eyaluatinn of the structural integrity nf Stnrage
Tunnel #1 in respunse tn questinns by the State uf Washingtun Department at' Eeblugy as
tn the adsisahility nf enntinuing to stare dangernus waste in Tunnel LATA ?nds that
there is very low probability of any degradatiun ut? the timbers in the tunnel due tn deeay
er inseet attack. The only structural degradatiun that is neeurring is due tn the enntinued
espusure ef the timbers tn the high ganuna radiatiun ?eld in the tunnel, and this e?eet is
rrdne-r. In the Silyan evaluatiun of the tunnel (Silvan 193m, the strength bf the timbers at
that time was determined tn be 155.4% at the nriginat strength. Based on the same rnethuds
ut? ealeulating radiatinn damage effects as used in the Silyan repurt, it is ennseryatlyely
estimated that the strength bf the timbers will be 613% {If un'ginal strength in the year 
At that time it is reennunended that the stnietura] integrity ef the tunnel he reevaluated in
light at tests being enndueted by the United States Furest Prnduet Labnratery and uthers
an the resistance of treated weed tn damage by decay ur inseet attaelt.